LineageOS/android_packages_modules_Connectivity
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Support strict mode private DNS on VPNs that provide Internet.

Browse Source 
Currently, strict mode private DNS does not work on VPNs because
NetworkMonitor does not validate VPNs. When a VPN connects, it
immediately transitions to ValidatedState, skipping private DNS
hostname resolution.

This change makes NetworkMonitor perform private DNS hostname
resolution and evaluation even on VPNs.

In order to ensure that the system always immediately switches to
the VPN as soon as it connects, remove the unvalidated penalty
for VPN networks. This ensures that the VPN score is always 101
and the VPN always outscores other networks as soon as it
connects. Previously, it would only outscore other networks
when no-op validation completed.

Backport of c455822846.

Bug: 122652057
Test: atest FrameworksNetTests
Test: manually ran a VPN with private DNS in strict mode
Test: atest android.net.cts.ConnectivityManagerTest com.android.cts.net.HostsideVpnTests
Change-Id: Iaa78a7edcf23755c89d7b354edbc28d37d74d891
Merged-In: Iaa78a7edcf23755c89d7b354edbc28d37d74d891
This commit is contained in:
Lorenzo Colitti
2019-05-10 04:33:43 -07:00
parent 7c9b1c757a
commit b316f633e5
3 changed files with 29 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
services/core/java/com/android/server/ConnectivityService.java
View File

@@ -2349,9 +2349,8 @@ public class ConnectivityService extends IConnectivityManager.Stub
}
}
private boolean networkRequiresValidation(NetworkAgentInfo nai) {
return NetworkMonitor.isValidationRequired(
mDefaultRequest.networkCapabilities, nai.networkCapabilities);
private boolean networkRequiresPrivateDnsValidation(NetworkAgentInfo nai) {
return nai.networkMonitor.isPrivateDnsValidationRequired();
}
private void handleFreshlyValidatedNetwork(NetworkAgentInfo nai) {
@@ -2369,16 +2368,14 @@ public class ConnectivityService extends IConnectivityManager.Stub
for (NetworkAgentInfo nai : mNetworkAgentInfos.values()) {
handlePerNetworkPrivateDnsConfig(nai, cfg);
if (networkRequiresValidation(nai)) {
if (networkRequiresPrivateDnsValidation(nai)) {
handleUpdateLinkProperties(nai, new LinkProperties(nai.linkProperties));
}
}
}
private void handlePerNetworkPrivateDnsConfig(NetworkAgentInfo nai, PrivateDnsConfig cfg) {
// Private DNS only ever applies to networks that might provide
// Internet access and therefore also require validation.
if (!networkRequiresValidation(nai)) return;
if (!networkRequiresPrivateDnsValidation(nai)) return;
// Notify the NetworkMonitor thread in case it needs to cancel or
// schedule DNS resolutions. If a DNS resolution is required the

4
services/core/java/com/android/server/connectivity/NetworkAgentInfo.java
View File

@@ -432,11 +432,11 @@ public class NetworkAgentInfo implements Comparable<NetworkAgentInfo> {
// down an explicitly selected network before the user gets a chance to prefer it when
// a higher-scoring network (e.g., Ethernet) is available.
if (networkMisc.explicitlySelected && (networkMisc.acceptUnvalidated || pretendValidated)) {
return ConnectivityConstants.MAXIMUM_NETWORK_SCORE;
return ConnectivityConstants.EXPLICITLY_SELECTED_NETWORK_SCORE;
}
int score = currentScore;
if (!lastValidated && !pretendValidated && !ignoreWifiUnvalidationPenalty()) {
if (!lastValidated && !pretendValidated && !ignoreWifiUnvalidationPenalty() && !isVPN()) {
score -= ConnectivityConstants.UNVALIDATED_SCORE_PENALTY;
}
if (score < 0) score = 0;

28
tests/net/java/com/android/server/ConnectivityServiceTest.java
View File

@@ -26,6 +26,7 @@ import static android.net.ConnectivityManager.TYPE_MOBILE;
import static android.net.ConnectivityManager.TYPE_MOBILE_FOTA;
import static android.net.ConnectivityManager.TYPE_MOBILE_MMS;
import static android.net.ConnectivityManager.TYPE_NONE;
import static android.net.ConnectivityManager.TYPE_VPN;
import static android.net.ConnectivityManager.TYPE_WIFI;
import static android.net.NetworkCapabilities.NET_CAPABILITY_CAPTIVE_PORTAL;
import static android.net.NetworkCapabilities.NET_CAPABILITY_CBS;
@@ -388,7 +389,7 @@ public class ConnectivityServiceTest {
MockNetworkAgent(int transport, LinkProperties linkProperties) {
final int type = transportToLegacyType(transport);
final String typeName = ConnectivityManager.getNetworkTypeName(transport);
final String typeName = ConnectivityManager.getNetworkTypeName(type);
mNetworkInfo = new NetworkInfo(type, 0, typeName, "Mock");
mNetworkCapabilities = new NetworkCapabilities();
mNetworkCapabilities.addTransportType(transport);
@@ -1111,6 +1112,8 @@ public class ConnectivityServiceTest {
return TYPE_WIFI;
case TRANSPORT_CELLULAR:
return TYPE_MOBILE;
case TRANSPORT_VPN:
return TYPE_VPN;
default:
return TYPE_NONE;
}
@@ -4468,7 +4471,7 @@ public class ConnectivityServiceTest {
callback.expectAvailableThenValidatedCallbacks(mEthernetNetworkAgent);
callback.assertNoCallback();
// Bring up a VPN that has the INTERNET capability but does not provide Internet access.
// Bring up a VPN that has the INTERNET capability but does not validate.
final int uid = Process.myUid();
final MockNetworkAgent vpnNetworkAgent = new MockNetworkAgent(TRANSPORT_VPN);
vpnNetworkAgent.getWrappedNetworkMonitor().gen204ProbeResult = 500;
@@ -4481,8 +4484,8 @@ public class ConnectivityServiceTest {
vpnNetworkAgent.connect(false /* validated */, true /* hasInternet */);
mMockVpn.connect();
// The VPN validates and becomes the default network for our app.
callback.expectAvailableCallbacksValidated(vpnNetworkAgent);
// Even though the VPN is unvalidated, it becomes the default network for our app.
callback.expectAvailableCallbacksUnvalidated(vpnNetworkAgent);
// TODO: this looks like a spurious callback.
callback.expectCallback(CallbackState.NETWORK_CAPABILITIES, vpnNetworkAgent);
callback.assertNoCallback();
@@ -4492,9 +4495,24 @@ public class ConnectivityServiceTest {
assertEquals(vpnNetworkAgent.getNetwork(), mCm.getActiveNetwork());
NetworkCapabilities nc = mCm.getNetworkCapabilities(vpnNetworkAgent.getNetwork());
assertTrue(nc.hasCapability(NET_CAPABILITY_VALIDATED));
assertFalse(nc.hasCapability(NET_CAPABILITY_VALIDATED));
assertTrue(nc.hasCapability(NET_CAPABILITY_INTERNET));
assertFalse(vpnNetworkAgent.getWrappedNetworkMonitor().isValidationRequired());
assertTrue(vpnNetworkAgent.getWrappedNetworkMonitor().isPrivateDnsValidationRequired());
// Pretend that the strict mode private DNS hostname now resolves. Even though the
// connectivity probe still returns 500, the network validates because the connectivity
// probe is not used on VPNs.
vpnNetworkAgent.getWrappedNetworkMonitor().dnsLookupResults =
new InetAddress[]{ InetAddress.getByName("2001:db8::1") };
mCm.reportNetworkConnectivity(vpnNetworkAgent.getNetwork(), true);
// Expect to see the validated capability, but no other changes, because the VPN is already
// the default network for the app.
callback.expectCapabilitiesWith(NET_CAPABILITY_VALIDATED, vpnNetworkAgent);
callback.assertNoCallback();
vpnNetworkAgent.disconnect();
callback.expectCallback(CallbackState.LOST, vpnNetworkAgent);
callback.expectAvailableCallbacksValidated(mEthernetNetworkAgent);